As for many recent car models, the Leaf does not have a keypad to unlock the door if you accidentally lock yourself out. I know that it is supposed to be impossible to lock the fob in the car, but I don't want to be the first to accidentally discover a way. Or maybe some day I'll use the aluminum foil idea to purposely hide the fob in the car on some special occasion.

So I wanted to hide just the mechanical key somewhere on the outside of the car.

A locksmith cut a duplicate mechanical key, using a conventional blank (no need for the H0564-1FA0B that fits in the fob).

As there's so little metal in any places I could find, and as the common magnetic hide-a-key cases have magnets that are too weak, I wanted a better method. So I bought two super-strong neodymium bar magnets, each 2" x ½", and wrapped them in tape in the hope they won't rust.

I put the spare key in a small plastic bag (so it wouldn't rust) and then put both the spare key and one magnet into a larger zip-lock bag.

I found that under the rear bumper there's an opening. You can reach your hand inside and put the rolled-up bag there, towards the back. Put the other magnet on the bottom of the bumper, opposite the magnet inside in the rolled-up bag.

The magnet in the zip-lock bag is covered in white tape, the magnet going under the bumper is in clear tape.

Here's the magnet under the bumper, the rolled-up zip-lock bag is above it, inside the rear bumper, reached through the opening towards the front of the car.

Get some latex gloves and a spare key and a tube of black silicone squeeze some silicone into your gloved hand then add the key squeeze a big gob more of silicone and find a convenient spot under the car or bumper stick the whole gob where you can pry it loose with something if you need it. First time it rains it will turn grey and look like a glob of mud under the frame but the key will be bone dry and ready to use and anyone will never know it is there .

I just keep the spare flat key in my wallet which only leaves my pocket on those rare occasions when I actually purchase something or to let the moths out. I admit it that I am cheap but then maybe that is why I was able to pay cash for my Leaf. ;>